Electric power generation from different fuel sources and technologies from 1990 to 2017. Since 2010, the declining market share from coal has been filled largely by natural gas and, to a lesser extent, renewables such as solar and wind power.
This is Figure 4.3 in "Impacts, Risks, and Adaptation in the United States: Fourth National Climate Assessment, Volume II." Public domain. Figure was adapted from "Electricity generation from selected fuels" figure in the 2018 Annual Energy Outlook (EIA 2018).